Roller Follower Cam

A roller follower cam designed to produce a set follower motion: a rise, a dwell at the top, and a return. The profile was developed from a given displacement diagram and modelled in SolidWorks.

A cam is designed in reverse. You start with the motion the follower needs to make, draw it as a displacement diagram, and the shape of the cam comes out of that. Every point on the profile has to come from the diagram.

The displacement diagram sets the follower position at each cam angle. The profile is built from it point by point, offset for the roller radius, then modelled as a solid.

A roller follower rolls on the cam instead of sliding across it, which reduces friction and wear.

This was the hardest of my design studies. The profile cannot be drawn by eye, and because of the roller radius, the cam surface and the path of the roller centre are two different curves. Most of the work is making the transitions between rise, dwell and return smooth, because a sharp corner in the profile becomes a shock load on the follower.